In agricultural productions, damages caused by pests have always been an important factor that influences the agricultural outputs. Every year, a large sum of human and material resources are consumed to reduce damages caused by pests in order to improve crop yields. However, wide spread applications of agriculture chemicals result in serious environmental contamination and cause severe damages to biodiversity in farms. Residual pesticides in farm products are also an important factor threatening human health. At the same time, long-term use of pesticides increases their resistance to the pesticides, resulting in ever increasing dosages of pesticides and changing the types of pesticides. This further exacerbates the environmental problems. In consideration of environmental protection and sustainable development, new methods for fighting pests are urgently needed.
Inserting insect-resistant genes, such as the Bt gene, into plants to produce insecticidal proteins in the plants can significantly improve plants' resistance to insects or pests. At the same time, this can reduce the applications of pesticides. At present, insect-resistant transgenic soybeans, Bt cotton, etc., have been widely cultivated, leading to great economic and social benefits. However, insect resistances against these proteins have been observed, and performances of these transgenic crops are also decreased. In addition, exclusively suppressing one specific insect can also lead to the boosts of other insects. Therefore, it is necessary to develop new insect-resistant transgenic plants in order to effectively and/or specifically counter the damages caused by pests.